Steering column for a motor vehicle and method for producing a steering column

ABSTRACT

A steering column for a motor vehicle may include a steering shaft that is rotatably supported in a cover unit, an interface for fitting a steering column switch fixed relative to the cover unit, and a transmission element connected to the steering shaft so as to conduct torque by way of a securing means. The transmission element may include actuation means that is movable into operational engagement with the steering column switch fitted to the interface. The transmission element may be constructed in one piece together with at least one securing means for a rotationally secure connection to the steering shaft.

PRIOR ART

The invention relates to a steering column for a motor vehicle, having asteering shaft which is rotatably supported in a cover unit and aninterface for fitting a steering column switch which is fixed relativeto the cover unit, and having a transmission element which is connectedto the steering shaft so as to conduct torque by way of a securing meansand which comprises at least one actuation means which can be moved intooperational engagement with the steering column switch which is fittedto the interface.

In a motor vehicle, the steering column serves firstly to transmitsteering commands from the steering wheel which is fitted at the rearend of the steering shaft to the steering gear mechanism, generally withan auxiliary force being coupled to reinforce the manual steering torqueintroduced into the steering wheel. Furthermore, the cover unit whichreceives at the bodywork side the rotatable support of the steeringshaft generally acts as a carrier for electrical switching and operatingelements which can be manually activated during travel, such as, forexample, indicator, headlight and windshield wiper switches. To thisend, in most cases a plurality of switching and operating elements arecombined in a steering shaft switch which is assembled as a modularsubassembly on the cover unit.

In order to receive the steering column switch, there is constructed onthe cover unit an interface which corresponds to securing devices on thesteering column switch and which, for example, may have defined abutmentfaces, securing elements and the like for positionally correct fixing ofthe steering column switch to the steering column. The interface ispreferably constructed in such a manner that the steering column switchcan be assembled during production on the steering column which isalready mounted in the vehicle.

In a generic steering column, the steering column switch is not onlymechanically secured to the interface, but instead a rotational movementof the steering shaft is also transmitted to the steering column switchin order to actuate switching elements by means of a steering movement,for instance, a return device for independent return of the indicatorswitch after a turning maneuver. The transmission of the rotationalmovement is carried out by means of a transmission element which iscoupled to the steering shaft in a rotationally secure manner and whichhas at least one actuation means which protrudes with respect to thesteering shaft and which when the steering shaft is rotated cooperateswith a corresponding switching element of the steering column switchwhich is fitted to the interface. For example, the actuation means mayhave an eccentric cam or journal which, in the event of a rotation ofthe steering shaft, moves a switching lever or trigger mechanism of thesteering column switch.

In the prior art, for example, in DE 199 20 994 A1, a transmissionelement for a steering column is described. The transmission elementwhich is described therein as a rotary connector has pin-like, axiallyprotruding positive-locking elements which are connected in apositive-locking manner to a steering wheel which is itself secured in arotationally secure manner to the steering shaft. Although atorque-conducting connection is thereby achieved with the steeringshaft, it is disadvantageous that, as a result of the successiveconnections between the transmission element and steering wheel andbetween the steering wheel and steering shaft, a high level ofcomplexity for complying with the predetermined tolerance requirementsis produced.

From DE 720 718 a steering column is also known having a transmissionelement which is secured to the steering shaft so as to conduct torque.This transmission element is clamped to the steering shaft by way of asecuring means, that is to say, by means of a clamping screw which isradially screwed into the transmission element. It is disadvantageous inthis instance that the transmission element and the securing means haveto be produced and assembled individually which requires a correspondingproduction and assembly complexity. Furthermore, the steering columnwhich is disclosed therein has only one integrated electric switchingcontact and no interface for fitting a steering shaft switch. Thisarrangement is consequently unsuitable for use in modern motor vehicles.

In view of the problems set out above, an object of the presentinvention is to provide a steering column for a motor vehicle of thetype mentioned in the introduction which can be produced and assembledin a simpler and more cost-effective manner.

STATEMENT OF INVENTION

In order to solve the above-mentioned problem, it is proposed accordingto the invention that the transmission element be constructed in onepiece together with at least one securing means for rotationally secureconnection to the steering shaft.

According to the invention, the transmission element comprises asingle-piece basic structure in which the securing means is/areintegrated in one piece. This construction type makes provision for theat least one securing means to be constructed as an integral functionalcomponent of the transmission element which, during production, isproduced directly on the transmission element. The requiredfunctionality for rotationally secure, that is to say, torque-conductingconnection to the steering shaft may be provided in this manner simplyby the configuration of the transmission element, by means of acorresponding single-piece shaping during the production. The termone-piece is intended to be understood to be a single-piece integralcomponent.

The single-piece construction of the transmission element and securingmeans according to the invention has the advantage that no furthersecuring means, such as screws, clamping or tensioning elements, have tobe produced and provided separately, whereby the production and costcomplexity is reduced. Furthermore, the connection of the securingelement to the transmission element is dispensed with, whereby the workand time complexity during the production of the steering column isadvantageously reduced.

The solution according to the invention is particularly suitable forsteering columns which are connected to a steering wheel and which havean integrated superimposition gearbox, a socalled active front steering.These superimposition gearboxes serve to introduce an additionalsteering angle in the steering shaft.

There may be provision for the securing means to comprise at least onepositive-locking element which engages in a correspondingpositive-locking receiving member of the steering shaft. Apositive-locking element may comprise a projection, journal or the likewhich is formed in one piece on the transmission element and whichprotrudes radially and/or axially and which engages in a correspondingradial or axial recess or indentation in the steering shaft, forexample, an axial groove, so that with respect to a movement in theperipheral direction a positive-locking, rotationally secure connectionis produced. A transposed arrangement with a projection which protrudesradially and/or axially from the steering shaft and which engages in acorresponding recess or indentation of the securing means is alsopossible, as is a combination of projections and recesses.

It is also conceivable and possible for the securing means to comprise aknurling or profiling which is in abutment in a positive-locking manneragainst a diametrically opposed surface of the steering shaft so that amicro-positive-locking connection is formed. Furthermore, it isconceivable and possible for the securing means to have a radialknurling and for the steering shaft to comprise a peripheral knurlingwith protrusions which extend at least partially in the peripheraldirection, wherein as a result of pressing the transmission element ontothe steering shaft, the axial knurling which is formed as a securingmeans is introduced into the peripheral knurling of the steering shaftand consequently a positive-locking connection is provided between thetransmission element and steering shaft.

The securing means may comprise at least one non-positive-lockingelement which is connected to the steering shaft in a frictionallyengaging manner. The non-positive-locking element comprises a surface ofthe transmission element which contacts a surface of the steering shaftin a frictionally engaging manner so that, as a result of the activestatic friction, a torque-conducting connection between the steeringshaft and transmission element is produced. A nonpositive-lockingelement may be provided, for example, by means of an axialthrough-opening by means of which the transmission element is pressed inan axial direction onto a securing portion of the steering shaft.

The securing means may have integrally constructed positive-locking andnon-positive-locking elements in combination. The securing portion ofthe steering shaft to which the transmission element is secured ispreferably constructed so as to correspond to the securing means of thetransmission element. This is intended to mean that there are arrangedin the securing portion positive-locking receiving members and/ornon-positive-locking receiving members which can be connected in atorque-conducting manner to the securing means of the transmissionelement.

It is further possible for the securing means to comprise at least oneresilient element. A resilient element may be clamped between thetransmission element and the steering shaft so that the transmissionelement is resiliently supported against the steering shaft. Theresilient force which is applied against the surface of the steeringshaft may bring about a defined non-positive-locking connection betweenthe transmission element and the steering shaft. Furthermore, any playwhich is present between the transmission element and steering shaft canalso be compensated for so that the transmission element is resilientlyfixed in a radial direction, even when the actual torque-conductingconnection is carried out via positive-locking elements. It is alsoconceivable and possible for a resilient element to clamp apositive-locking element in positive-locking engagement in a resilientmanner so that a secure and play-free fit is ensured. The resilientelement is preferably constructed in an integral manner with thetransmission element.

There are preferably arranged on the transmission element a plurality ofresilient elements which in a state distributed over the periphery in arotationally symmetrical manner are resiliently pretensioned radiallyagainst the outer covering face of the steering shaft. In a particularlypreferred manner, three resilient elements are each arranged offset withrespect to each other through 120° with respect to the periphery of thesteering shaft so that the transmission element is retained in acentered manner on the steering shaft by means of the radial resilientforces. Alternatively, four, five or six resilient elements may also beprovided.

The resilient element(s) is/are preferably formed in an integral manneron the transmission element, for example, in an annular or tubularportion of the securing means in the form of slotted segments so thatthere are formed resilient tongues which can be supported in a resilientmanner against the steering shaft.

In its basic form, the transmission element may be constructed in anannular manner and at least partially engage around the steering shaftin a peripheral direction. There is thereby formed a ring which iscoaxially fitted and fixed on the steering shaft with thethrough-opening thereof. The ring is preferably closed and completelysurrounds the steering shaft. In the region of the through-opening, thesecuring means may be produced according to the invention integrally onthe ring. In this instance, at least one securing means is arranged on aface of the transmission element facing the outer side of the steeringshaft, preferably on an inner face of the through-opening which isopposite an outer face of the steering shaft. The inner and outer facesmay comprise inner and outer covering faces which are opposite eachother in a radial direction, or end faces of the transmission elementand the steering shaft which face each other in an axial direction.

The transmission element may comprise an annular element in the form ofa flat annular disk, having a radial annular width which is measuredbetween the edge of the through-opening and the outer periphery andwhich is greater than or equal to the annular thickness in an axialdirection of the through-opening. In the region of the through-openingand/or the end faces, a securing means according to the invention may beintegrally formed on or in. At least one actuation means may be arrangedin the radially outwardly protruding region, preferably in the outerperipheral region. The actuation means may, for example, comprise aradially inwardly formed recess in which a corresponding switchingelement of a steering shaft switch which is fitted to the interfaceengages in a radial direction in a positive-locking manner.

It is advantageous for the securing means to comprise a securing sleevein the form of a tubular portion. According to the invention, thesecuring sleeve is configured in one piece with the transmissionelement, for example, integrally formed. With the through-openingthereof which corresponds to the cross-section of the steering shaft ina securing portion, the securing sleeve may be arranged and securedcoaxially on the steering shaft. In the region of the axial extentthereof, the securing sleeve may have as securing means one or morepositive-locking elements and/or non-positive-locking elements and/orresilient elements which can be connected to the steering shaft.Preferably, they are arranged on the inner face of the through-openingthereof so that they can be secured to the outer covering face of thesteering shaft. For example, the annular securing sleeve in order toform a non-positive-locking connection with press-fit can be pressedaxially onto the steering shaft, wherein the axial dimension is selectedto be so large that in a peripheral direction a fixed frictionallyengaging connection can be carried out. Alternatively or additionally,there may be arranged on the securing sleeve one or morepositive-locking elements which can be brought into engagement withcorresponding positive-locking receiving members on the steering shaftin an axial direction. These positive-locking elements may, for example,comprise one or more projections which protrude radially into thepassage cross-section and which can be inserted in an axial direction incorresponding axial grooves in the outer covering face. Alternatively oradditionally, there may be arranged on the securing sleeve one or moreresilient elements which resiliently protrude, for example, in aradially inward direction with respect to the passage cross-section. Aresilient element may, for example, be produced by axial slots which arearranged with spacing with respect to each other being introduced intothe tubular securing sleeve at one end in a peripheral direction so thatthe web which remains therebetween forms a leaf spring or resilienttongue which can be moved with the free end thereof resiliently in aradial direction. In this manner, two or more axial slots may also beintroduced in a state distributed over the periphery so that thesecuring sleeve is segmented over the entire periphery thereof and thesegments between the slots form a number of leaf springs or resilienttongues which corresponds to the number of slots. As a result of thefact that the resilient tongues are formed and sized in such a mannerthat they protrude radially inward in the unloaded state, when they areaxially placed on a steering shaft they are splayed radially outward andare in abutment with radial pretensioning against a securing portion ofthe steering shaft. A defined non-positive-locking can thereby beproduced between the securing means of the transmission element and thesteering shaft. Alternatively or additionally, as a result of theresilient elements, positive-locking elements such as those describedabove may be pretensioned in a resilient manner against each other.Furthermore, radial play between the transmission element and thesteering shaft can be compensated for and the transmission element canbe held in a resiliently centered manner on the steering shaft.

The securing sleeve may extend in an axial direction from an annularelement of the transmission element, for example, in the form of a ringor an annular disk, wherein the annular element protrudes in a radialdirection over the securing sleeve. The annular element may preferablyhave on the outer periphery thereof at least one actuation means whichhas, for example, a radially formed recess.

An advantageous embodiment makes provision for the transmission elementto be constructed as a sheet metal component. According to theinvention, such a molded sheet metal component including the securingmeans can be produced in a particularly rational manner by means ofpunching and/or optionally cold forming, preferably from sheet steel orspring steel sheet. An advantage of this production method is that, as aresult of the shaping, the mechanical properties can be adapted in aselective localized manner to the loads which occur, for example, bymeans of shaping beads or edges, the flexural strength can be increasedlocally, or by means of embossings the material thickness can be reducedin order to reduce the rigidity. It is thereby possible, for example, toadjust and adapt the resilient force of the resilient elements mentionedabove.

A transmission element which is constructed as a molded sheet metalcomponent, preferably of sheet steel or spring steel sheet may comprisepart-regions in which the material properties of the remaining regionsare constructed in a different manner. The part-regions may, forexample, have a greater or lesser hardness. Such an adjustment of thematerial properties may, for example, be carried out by means of localthermal processing, such as, for example, by means of laser beamhardening. It is thereby, for example, possible to adjust the retentionforce of the securing means on the steering shaft by means of localchange of the hardness.

At least one actuation means—for example, comprising radial and/or axialformations, recesses and/or projections—may also be formed in anintegral manner as a molded sheet metal component with the transmissionelement. Alternatively, the production as a press or cast component mayalso be carried out integrally with one or more securing elements.

The transmission element may alternatively be formed as a moldedplastics material component. The production as an injection-moldedcomponent provides great configuration freedom in terms of thesingle-piece shaping so that securing means according to the inventionand where applicable also actuation means can be readily integrated inone piece. A sufficient durability can be achieved by means of theselection of plastics materials with corresponding material properties,wherein, in order to increase the strength, reinforcement fibers can beadded, such as, for example, glass or carbon fibers. A particularlylight construction can thereby be achieved.

The interface preferably comprises on the cover unit a receiving portionwhich is arranged in an axial direction adjacent to the transmissionelement. The receiving portion may, for example, comprise a cylindricalor prismatic region which is arranged coaxially relative to the steeringshaft and on which the steering shaft switch, also referred tosynonymously as a steering shaft switch module, can be fitted in anaxial direction with a receiving member which corresponds in terms ofshape and dimensions. For assembly on the steering column which isalready installed in the motor vehicle, before the steering wheel isfitted the steering shaft switch module is fitted and fixed from thesteering-wheel-side rear end to the receiving portion of the cover unit,for example, by means of an engagement, screw connection or clamping. Inorder to ensure a clear orientation with respect to the steering axle,the receiving portion and the corresponding receiving member on thesteering shaft switch are provided with positive-locking elements whichcan be joined together only in a defined rotation position with respectto the steering axle. In order to simplify the assembly of the steeringshaft switch, an auxiliary assembly member in the form of a profiledsleeve can be placed on the steering-wheel-side end of the steeringshaft. The auxiliary assembly member comprises a guide channel whichextends starting from the steeringwheel-side end of the steering shaftto the actuation means of the transmission element. Preferably, theguide channel narrows starting from the steering-wheel-side end of thesteering shaft to the actuation means of the transmission element sothat a type of introduction funnel is provided.

A method according to the invention for producing a steering column fora motor vehicle, having a steering shaft which is rotatably supported ina cover unit and an interface for fitting a steering shaft switch whichis fixed relative to the cover unit, and having a transmission elementwhich is connected in a torque-conducting manner to the steering shaftby way of securing means, and which comprises at least one actuationmeans which can be brought into operational engagement with the steeringshaft switch which is fitted to the interface, makes provision for thetransmission element, which together with at least one securing means isconstructed in one piece for connection to the steering shaft, to befitted in an axial direction to the steering shaft and withoutadditional connection means to be fixed directly in a rotationallysecure manner to the steering shaft so as to be self-retaining.

In contrast to the prior art, in which an initially separate connectionmeans first has to be connected to the transmission element and, duringassembly, the transmission element has to be fixed on the steering shaftby clamping the connection means, the transmission element according tothe invention is produced and provided in one piece and in a productionstep is axially placed on the steering shaft. As a result of theintegral construction of the securing means, other operating steps aresuperfluous. The production of a steering column is thereby possible ina more rational manner.

For example, the transmission element can be pressed with the securingmeans in a frictionally engaging manner in an axial direction onto thesecuring portion of the steering shaft. Alternatively or additionally,one or more positive-locking elements which are formed on the securingmeans of the transmission element can be moved into engagement withcorresponding positive-locking receiving members on the transmissionelement in an axial direction.

In order to produce the steering column, after the transmission elementhas been fixed a steering shaft switch can be fitted to the interface ofthe cover unit indirectly or directly, wherein an actuation means of thetransmission element is moved into actuation engagement with thesteering shaft switch.

DESCRIPTION OF THE DRAWINGS

Advantageous embodiments of the invention are explained in greaterdetail below with reference to the drawings, in which:

FIG. 1 is a schematic, perspective illustration of a steering columnhaving a steering shaft switch which is fitted thereto,

FIG. 2 is a detailed view of the steering column from FIG. 1,

FIG. 3 shows the steering column according to FIG. 1 in an axiallyseparated state,

FIG. 4 is an axial view of the rear end of the steering column accordingto FIG. 1,

FIG. 5 is a partial longitudinal section in the direction of thelongitudinal axis through the steering column according to FIG. 1,

FIG. 6 is a schematic perspective view of a steering shaft in a firstembodiment,

FIG. 7 is an axial view of the steering shaft according to FIG. 6,

FIG. 8 is a schematic perspective view of a steering shaft in a secondembodiment,

FIG. 9 shows the transmission element of the steering shaft from FIG. 8in the removed state,

FIG. 10 shows the transmission element according to FIG. 9 in theseparated state.

EMBODIMENTS OF THE INVENTION

In the different figures, identical components are always given the samereference numerals and are therefore generally also only set out ormentioned once.

FIG. 1 shows a steering column 1 according to the invention as aperspective view obliquely toward the rear end on which in the vehicle asteering wheel which is not illustrated in this instance is assembled.

Via the retention unit 11, the steering column 1 can be secured to avehicle bodywork which is not illustrated in this instance. Theretention unit 11 has two downwardly protruding side members 12 betweenwhich the outer cover pipe 14 of an actuation unit 13 is arranged. Inthe cover pipe 14, a steering shaft 15 is rotatably supported about thelongitudinal axis 16 thereof. At the rear end region of the steeringshaft 15, a portion 151 for fitting a steering wheel which is notillustrated is formed.

By means of a clamping device which has a clamping axle 17 which extendsthrough both side members 12 transversely relative to the longitudinalaxis 16, the side members 12 can be pressed by means of manual movementof an actuation lever 18 from the outer side against the cover pipe 14and consequently tensioned. Different construction types of clampingdevices which implement a rotational movement of the actuation lever 18in order via the clamping axle 17 to pull the side members against eachother are known in the prior art, for example, as cam or tilting pinclamping devices. In the secured state of the clamping device, the coverpipe 14 is clamped between the side members 12 and consequently theactuation unit 13 is connected to the retention unit 11 in anon-positive and/or positive-locking manner so that the steering wheelposition is fixed in the vehicle inner space. In the released state ofthe clamping device, the clamping connection to the retention unit 11 isreleased so that the actuation unit 13 can be adjusted relative to theretention unit 11 in the direction of the longitudinal axis 16 and inmost cases also transversely relative thereto in the vertical direction19.

There is fitted to the actuation unit 13 a steering shaft switch 2 whichis constructed as a steering shaft switch module which generallycombines a plurality of electrical switching devices, in the illustratedembodiment, for example, an indicator switch 21 with a manuallyactuatable switch lever, and, for example, a headlight switch, also witha switch lever.

FIGS. 2 and 3 show detailed views of the steering column 1, wherein FIG.3 shows a separated view prior to assembly. The steering shaft switch 2has a continuous securing opening 22 which for assembly is placed fromthe rear parallel with the longitudinal axis 16 on an interface 3 whichis formed on the actuation unit 13, as indicated in FIG. 3 with thearrow. The interface 3 has in the example illustrated a cylindricalreceiving portion 31 on the cover pipe 14 which can be insertedcoaxially in a positive-locking manner in a correspondinghollow-cylindrical counter-portion 23 in the securing opening 22.Furthermore, there may be provided on the cover pipe 12 assemblyopenings 32 which can be connected by means of corresponding assemblyelements to the steering shaft switch 2.

On a securing portion 152 of the steering shaft 15, a transmissionelement 4 according to the invention is fitted in a rotationally securemanner in the region of the interface 3. The transmission element 4 islocated in the direction of the longitudinal axis 16 adjacent to thereceiving portion 31 so that it can be rotated together with thesteering shaft 15 relative to the receiving portion 31 about thelongitudinal axis 16.

The steering shaft switch 2 has a plurality of electrical switchelements which can be operated manually, including the indicator switch21.

In the region of the through-opening 22, the steering shaft switch 2 hasa carrier element 24 which in the assembly state shown in FIG. 2 islocated in the region of the interface 3 so that it is intorque-conducting operational engagement with the transmission element4. To this end, the carrier element 24 may have a journal 25 whichprotrudes radially inward into the through-opening 22 and which engageswith respect to the peripheral direction in a positive-locking manner ina corresponding actuation means of the transmission element 4 which inthe example illustrated is constructed as a radial formation 41 in theouter periphery of the transmission element 4. In order to improve theassembly of the steering shaft switch 2, an auxiliary assembly member155 in the form of a profiled sleeve which is formed from plasticsmaterial can be used, wherein the auxiliary assembly member 155 isplaced prior to the assembly of the steering shaft switch 2 on theportion 151 of the steering shaft 15. The auxiliary assembly member 155comprises a guide channel 156 which narrows from the steering-wheel-sideend of the steering shaft. The guide channel 156 guides the journal 25of the steering shaft switch module 2 during the assembly to theformation 41 of the transmission element 4. Consequently, the guidechannel 156 acts as an auxiliary introduction member for the couplingbetween the journal 25 and the formation 41. Consequently, the assemblycan be carried out in a secure and simple manner. After the assembly ofthe steering shaft switch, the auxiliary introduction member 155 can bereadily removed from the portion 151 of the steering shaft 15 andsubsequently the steering wheel can be assembled.

The carrier element 24 acts as an actuator for a return device of theindicator switch 21 which is not illustrated in detail. The returndevice deactivates the switched-on indicator switch 21 independentlywhen the steering shaft 15 is turned back after a turning maneuver.

FIG. 4 shows the assembled state from FIG. 2 again as an axial view fromthe rear. It can be seen how the carrier element 24 engages with thejournal 25 radially in the formation 41 and is thereby connected to thetransmission element 4 in a torque-conducting manner.

In FIG. 5, a longitudinal section through the actuation unit 13 in theregion of the interface 3 is illustrated. It can be seen therein how thetransmission element 4 is fitted on the securing portion 152 of thesteering shaft 15 axially adjacent to the receiving portion 31 of thecover pipe 14. The coupling between the cover pipe 14 and the steeringshaft switch 2 is, however, not carried out exclusively via thereceiving portion 31.

In an embodiment which is not illustrated, the steering shaft switch issecured to a metal plate which is orientated orthogonally with respectto the longitudinal axis of the steering shaft and which is secured tothe cover pipe. Other interfaces between the cover pipe and the steeringshaft switch are also conceivable and possible and sufficiently knownfrom the prior art.

The specific configuration of the transmission element 4 according tothe invention becomes clear together with the illustrations in FIGS. 6and 7. Accordingly, this embodiment of the transmission element 4 isconstructed in an annular manner and has the basic shape of a flatcircular ring or an annular disk which extends parallel with a radialplane of the steering shaft 15. This embodiment of the transmissionelement may, for example, be constructed as a molded sheet metalcomponent, preferably from sheet steel.

As already mentioned above, the transmission element 4 has in the outerperiphery thereof a radial formation 41 which forms an actuation meansfor torque-conducting coupling to the carrier element 24 of theindicator switch 21. There may be provided at least one other recess 42,where applicable also a plurality, for example, for actuatingcorresponding switch elements or the like. The recess 42 may also act asan auxiliary orientation member during the assembly of the transmissionelement 4 on the steering shaft 15.

For rotationally secure, that is to say, torque-conducting securing tothe steering shaft 15, the transmission element 4 has a positive-lockingelement 43 which protrudes radially into the annular opening thereof,and which engages in the corresponding longitudinal groove 153 in thesecuring portion 152 in a positive-locking manner. In addition,additional positive-locking elements 44 which engage in longitudinalgrooves 154 may be provided.

Furthermore, the securing means may comprise centering projections 45which also protrude radially inward into the open annular cross-section.Preferably, a plurality, in the example shown, six, of the centeringprojections 45 are arranged in a state distributed over the periphery.The centering projections 45 do not engage in a positive-locking manner,but are instead supported in a radial direction on the cylindrical outerperiphery of the steering shaft 15 and can ensure asnon-positive-locking elements a frictionally engaging connection.

The positive-locking elements 43, 44 and the centering projections 45form securing means according to the invention which are constructed inan integral manner with the transmission element 4. The transmissionelement 4 which is in the form of an annular disk in terms of its basicshape may be constructed as a stamped sheet metal component, preferablyof sheet steel.

Another embodiment of a transmission element 4 according to theinvention is illustrated in FIGS. 8, 9 and 10. This also has a flatannular disk 46 which has formations 42 in the outer periphery thereof.In place of the formation 41 of the first embodiment, there are providedin this instance engagement elements 47 to which there can be fitted ina radial direction an adapter piece 5 which itself has the formation 41for coupling to the carrier element 24 of the steering shaft switch 2.

For connection to the transmission element 4, the adapter piece hasconnection openings 51 in which the engagement elements 47 can bereceived in order to position and retain the adapter piece 5.Furthermore, it comprises in an axial direction resilient lockingelements 52 which can be brought axially into engagement with thethrough-opening of the annular disk 46 so that the adapter piece 5 issecurely engaged on the transmission element 4.

There is on the annular disk 46 a tubular-portion-like, conicallyconverging securing sleeve 48 which has multiple slots over theperiphery thereof in order to form a plurality of segment-like resilientelements 49. The passage cross-section which is formed inside theseresilient elements 49 is sized in such a manner that the securing sleeve48 can be axially pressed onto the securing portion 152 of the steeringshaft 15, wherein the resilient elements 49 as a result of theirresilient force bring about a non-positive-locking connection of thetransmission element 4 to the steering shaft 15, that is to say, formnon-positive-locking elements for frictionally engaging connection andconsequently securing means in the context of the invention.

According to the invention, the resilient elements 49 are constructedintegrally with the transmission element 4. Preferably, the secondillustrated embodiment of the transmission element 4 is also constructedas a sheet metal component, preferably as a cold-formed pressed andpunched component of sheet steel or spring steel sheet.

The adapter component 5 which is optionally provided may, for example,be constructed as a plastics material injection-molded component whichcan be produced in a favorable manner and which enables particularlysimple structural adaptation of a single-piece transmission element 4according to the invention to different types of steering columns 1 orembodiments of steering shaft switches 2.

The solution according to the invention is not limited to a steeringcolumn which can be adjusted manually in a vertical and/or longitudinaldirection. Instead, the solution according to the invention may, forexample, also be used with steering columns which can be adjusted in amotorized manner or which are non-adjustable.

List of reference numerals 1 Steering column 11 Retention unit 12 Sidemember 13 Actuation unit 14 Cover pipe 15 Steering shaft 151 Portion 152Securing portion 153 Longitudinal groove 154 Longitudinal groove 155Auxiliary assembly member 156 Guide channel 16 Longitudinal axis 17Clamping axle 18 Actuation lever 19 Vertical direction 2 Steering shaftswitch 21 Indicator switch 22 Securing opening 23 Counter-portion 24Carrier element 25 Journal 3 Interface 31 Receiving portion 32 Assemblyopening 4 Transmission element 41 Formation 42 Recess 43Positive-locking element 44 Positive-locking element 45 Centeringprojection 46 Annular disk 47 Engagement element 48 Securing sleeve 49Resilient elements 5 Adapter piece 51 Connection opening 52 Lockingelement

1.-10. (canceled)
 11. A steering column comprising: a steering shaftthat is rotatably supported in a cover unit; an interface for fitting asteering column switch that is fixed relative to the cover unit; and atransmission element that is securely and rotatably connected to thesteering shaft by way of securing means so as to conduct torque, whereinthe transmission element is formed as an integral piece with thesecuring means, the transmission element comprising actuation means thatis movable into operational engagement with the steering column switchfitted to the interface.
 12. The steering column of claim 11 wherein theintegral piece is a single piece.
 13. The steering column of claim 11wherein the securing means comprises a positive-locking element thatengages in a corresponding positive-locking receiving member of thesteering shaft.
 14. The steering column of claim 11 wherein the securingmeans comprises a non-positive locking element that is connected to thesteering shaft in a frictionally engaging manner.
 15. The steeringcolumn of claim 11 wherein the securing means comprises a resilientelement.
 16. The steering column of claim 11 wherein the transmissionelement is annular and at least partially engages around the steeringshaft in a peripheral direction.
 17. The steering column of claim 11wherein the securing means comprises a securing sleeve configured as atubular portion.
 18. The steering column of claim 11 wherein thetransmission element is a sheet metal component.
 19. The steering columnof claim 11 wherein the interface comprises on the cover unit areceiving portion that is disposed in an axial direction adjacent to thetransmission element.
 20. A method for producing a steering column thatincludes a steering shaft that is rotatably supported in a cover unit,an interface for fitting a steering shaft switch that is fixed relativeto the cover unit, and a transmission element that is connected in atorque-conducting manner to the steering shaft by way of securing meansand that comprises actuation means configured to be brought intooperational engagement with the steering shaft switch fitted to theinterface, the method comprising: fitting the transmission element,which is formed as an integral piece with the securing means forconnection to the steering shaft, in an axial direction to the steeringshaft; and fixing the transmission element, without additionalconnection means, directly in a rotationally secure manner to thesteering shaft so as to be self-retaining.
 21. The method of claim 20comprising, after fixing the transmission element to the steering shaft,fitting the steering shaft switch to the interface of the cover unitdirectly or indirectly, wherein the actuation means of the transmissionelement is brought into operational engagement with the steering shaftswitch.
 22. The method of claim 20 wherein the integral piece is asingle piece.